Enzyme-linked immunosorbent assay for detection of equine infectious anemia antibody to purified P26 viral protein

An indirect enzyme-linked immunosorbent assay (ELISA) was developed for the detection of equine infectious anemia (EIA) antibody in horse sera. Purified P26 viral protein was the antigen; alkaline phosphatase linked to rabbit anti-horse immunoglobulin G was the conjugate. The ELISA detected EIA antibodies in horse sera as early as 11 to 14 days after experimental inoculations. There was full agreement between the results of ELISA and the agar-gel immunodiffusion tests on EIA proficiency test sera. The ELISA readily detected EIA antibody in horse sera that had weak positive reactions on agar-gel immunodiffusion.     

Comparison of commercial enzyme-linked immunosorbent assays and agar gel immunodiffusion tests for the serodiagnosis of equine infectious anemia

The purpose of this study was to estimate the performance characteristics (accuracy, detection limit, and precision) of commercially available enzyme-linked immunosorbent assay (ELISA) and agar gel immunodiffusion (AGID) kits in comparison with a reference AGID kit for the detection of equine infectious anemia (EIA) antibodies in horses for regulatory use in Canada. A total of 285 positive and 315 negative samples by the reference AGID were tested blindly on 2 other AGID and 4 ELISA kits. Commercially available AGID kits for the serodiagnosis of EIA were found equivalent. The 3 ELISAs directed against antibodies to the p26 core protein also performed relatively well in comparison with the reference AGID, with excellent relative accuracy and acceptable precision. The single ELISA directed against antibodies to the gp45 trans-membrane viral protein yielded a lower relative sensitivity. The performance characteristics of the ELISAs directed against antibodies to p26 are, therefore, adequate to support the implementation of ELISA for regulatory purposes in Canada.     

马传染性贫血病毒p26蛋白单克隆抗体的制备

为制备马传染性贫血病毒(EIAV)的单克隆抗体(MAb),本研究以原核表达并纯化的EIAV p26蛋白作为免疫原免疫8周龄的BALB/c小鼠,利用淋巴细胞杂交瘤技术,建立抗EIAV衣壳蛋白p26抗体的杂交瘤细胞.应用重组p26蛋白为抗原建立ELISA筛选方法,获得两株能够稳定分泌特异性MAb的杂交瘤细胞株,分别命名为E11和F8.经试验证明,这些抗p26MAb均能够与感染驴胎皮肤细胞的EIAV和经SDS-PAGE分离的EIAV总蛋白中的p26蛋白结合.这两株p26蛋白MAb的获得将为EIAV的检测及鉴别诊断奠定基础.     

马传染性贫血琼扩抗原生产工艺的改进

马传染性贫血病毒(Equine infectious anemia virus，EIAV)是逆转录病毒科慢病毒属的成员之一，其基因组结构与人免疫缺陷病毒Ⅰ型(Human innunodeficiency virus type 1，HIV-Ⅰ)相似。马传染性贫血呈世界性分布，常引起慢性感染，以发热、贫血为特征，耐过马呈隐性感染并终身带毒。20世纪70年代初期，Coggins博士建立了检测感染马血清抗体的琼脂扩散试验(AGID)，成为检测EIA的标准方法。     

Cross-neutralizing and subclass characteristics of antibody from horses with equine infectious anemia virus

Antibody responses in horses with equine infectious anemia virus (EIAV) were examined to determine their cross-neutralizing capacity. Antibodies induced by infection with any of six biologically cloned variants of EIAV cross-neutralized multiple variants from the group. Anti-EIAV antibody was found in both the IgG and IgG(T) subclasses in plasmas with virus-neutralizing activity and the majority of antiviral antibody was of the IgG(T) subclass. Depletion of IgG(T) did not increase the neutralization indexes of either neutralizing or non-neutralizing plasma samples.     

Enzyme-linked immunosorbent assay for diagnosis of equine infectious anemia

An enzyme-linked immunosorbent assay (ELISA) was elaborated for the detection of specific antibody to equine infectious anemia (EIA) antigen. Sera from horses experimentally infected with EIA virus were assayed by ELISA, complement fixation (CF) and immunodiffusion (ID) tests for antibody to EIA antigen. The ELISA technique was found to be much more sensitive than CF and ID tests. In addition, EIA specific antibody could be detected by ELISA at an earlier stage of infection than by CF or ID techniques. The applicability of the technique to diagnosis of EIA is discussed.     

马传染性贫血病毒自然感染马LTR序列分析

我国从20世纪70年代开始使用EIAV弱毒疫苗后,在全国范围内基本控制了马传贫的发生,我们从现地少数EIAV琼扩阳性马外周血中扩增并克隆了二株EIAV前病毒5'LTR序列,并与国内外毒株5'LTR序列进行了比较分析,发现中国EIAV LTR特有的特异性细胞转录因子结合基序,同时发现PEA2位点不是强毒特有的基序,在弱毒中亦发现该基序.     

带有组氨酸标签的马传染性贫血病毒感染性分子克隆的构建

马传染性贫血(EIA)弱毒疫苗的广泛使用存在野毒和疫苗毒鉴别困难的问题.本研究以已构建的马传染性贫血驴白细胞弱毒疫苗株的感染性分子克隆(pOK8266)为基础,在其S2基因内引入NspV酶切位点,将人工合成的编码6个组氨酸的寡核苷酸插入NspV位点,获得带有组氨酸标签的重组质粒pOK8266-HIS.将pOK8266-HIS转染驴白细胞,将驴白细胞转染产物传至第6代时,在电镜下观察到了典型的马传染性贫血病毒粒子.提取pOK8266-HIS衍生病毒的前病毒基因组DNA,通过PCR扩增和测序表明,衍生病毒基因组中引入了6个组氨酸标签,从而获得了带有分子标志的马传染性贫血弱毒疫苗株,为野毒株和疫苗病毒的鉴别诊断奠定了基础.本研究还证明了S2基因中的插入突变并不影响马传染性贫血病毒的体外复制.